The class of barbiturate derivatives is extensive and in general they are characterized by the amide urea ring with various alkyl substituents off the 5' position. Barbiturates are used as sedatives, hypnotics and to control seizures. The class of barbiturates includes, but is not limited to, amobarbital, aprobarbital, barbital, butabarbital, mephobarbital, pentobarbital, phenobarbital and secobarbital. The illicit and excessive use of barbiturates has resulted in a medical need for antibodies and diagnostics to rapidly detect the barbiturate metabolites in order to monitor and treat barbiturate addiction.
The preparation of antibodies to barbiturate metabolites requires the synthesis of a barbiturate derivative in order to covalently attach the derivative to an antigenic polypeptide or protein. In addition, the barbiturate derivative is covalently attached to various polypeptides, proteins or labels for use in screening antibodies and in the immunoassay process. The barbiturate derivative should mimic the structure of the class of barbiturate metabolites sought to be measured. Therefore, the selection and synthesis of the types of barbiturate derivatives for covalent attachment to proteins, polypeptides or labels is critical. In addition, the barbiturate derivatives need to be stable and soluble in an aqueous solution.